Pump sterilization process and pumping system suitable for applying the process

Abstract

A process for the sterilization of pumps for liquid or pasty pharmaceuticals, cosmetics, foodstuffs or similar products, preferably for pumps in which the piston can be driven to slide longitudinally in a cylinder and, at the same time, to rotate about its own axis. The piston contains a recess that reaches as far as the circular cylinder wall and the working face of the piston and communicates with a suction connection in the cylinder wall during a suction stroke and with a pressure connection in the cylinder wall during a pressure stroke and where, further, a closable drainage aperture is preferably provided in the bottom end of the cylinder. A sterilization medium is fed to a pump connection while the pump is being driven. Consequently, the pump does not have to be dismantled for sterilization purposes.

What is claimed is: 
     
       1. Process for the sterilization of pumps for liquid or pasty pharmaceuticals, cosmetics, foodstuffs or similar products, each of said pumps including a piston adapted to slide longitudinally in a cylinder and, at the same time, to rotate about its own axis, the piston including a longitudinal recess adjacent a circular cylinder wall and extending to a working face of the piston, said recess communicating with a suction connection in the cylinder wall during a suction stroke of the piston and with a pressure connection in the cylinder wall during a pressure stroke of the piston said cylinder including a closable drainage aperture in a bottom end thereof said process comprising the step of feeding a sterilization medium to one of the suction and pressure connections while the pump is being driven. 
     
     
       2. The process according to claim 1 further comprising the step of rotating the piston constantly in the same direction as the sterilization medium is fed into one of the suction and pressure connections. 
     
     
       3. A pumping system for liquid or pasty pharmaceuticals, cosmetics, foodstuffs or similar products comprising at least one pump with a ceramic piston disposed with a ceramic cylinder and means for longitudinally sliding the piston in a generally vertical direction within the cylinder and for rotating the piston around a longitudinal axis thereof, the piston containing a recess therein adjacent a circular cylinder wall and extending to a working face of the piston, said recess communicating with a suction connection in the cylinder wall during a suction stroke of the piston and with a pressure connection in the circular cylinder wall during a pressure stroke of the piston, the cylinder including a closable aperture disposed in a bottom of the cylinder. 
     
     
       4. The pumping system according to claim 3 wherein the cylinder bottom is enclosed with respect to the horizontal. 
     
     
       5. The pumping system according to claim 3 wherein the cylinder has a length that essentially corresponds to a length of the piston plus a length of a piston working stroke. 
     
     
       6. The pumping system according to claim 3 wherein an upper end area of the cylinder terminates in a space that is near gastight and the pumping system further comprises a gas connection to the near gastight space.